upgrade to riak python client 2.x
upgrade riak version for travis
remove riak prefix, allow alter port numbers, update documentation
extend riak cache configuration to support multi node connections
fixed missing import of RiakObject and riak package warning
update spec as described in documentation
fixed setting default ports; make code more idiomatic
extend docs; use space instead of tabs
Merge pull request #112 from olt/riak-client-2.x

Riak client 2.x